A LEVEL CHEMISTRY OCR A - PAPER 1 Exam
d d d d d d d d d
Questions With Mark Scheme d d d
Q1 >>> Which atom is not an isotope of iodine ? [refer to the QP for the table] - ANSWER:*D*
d d d d d d d d d d d d d d d d d d d
Iodine has a proton number of 53
d d d d d d
Atom D [The element tellurium] has a proton number of 52
d d d d d d d d d d
Q2 >>> What is the bonding between the ligands and the metal ion in [Fe(H2O)6]2+ ?
d d d d d d d d d d d d d d d d
A - Metallic
d d d
B - Ionic
d d d
C - Hydrogen
d d d
D - Dative covalent - ANSWER:*D*
d d d d d
Ligand - metal ion bonds are coordinate bonds, which is a type of dative covalent bond
d d d d d d d d d d d d d d d
Q3 >>> What is the oxidation number of Mn in K2MnO4 ?
d d d d d d d d d d d d
A - +4
d d d
B - +5
d d d
C - +6
d d d
D - +7 - ANSWER:*C*
d d d d
, The 2x K+ ions each have an oxidation state of +1 so 1 x 2 = +2
d d d d d d d d d d d d d d d d d
The 4x O^2- ions each have an oxidation state of -2, so 2 x 4 = -8 in total
d d d d d d d d d d d d d d d d d d
-8 + +2 = -6, so an oxidation number of +6 is needed, as the overall oxidation state is 0
d d d d d d d d d d d d d d d d d d d
Q4 >>> Which calcium compound contains the greatest percentage by mass of calcium ?
d d d d d d d d d d d d d d
A - calcium carbonate
d d d d
B - calcium nitrate
d d d d
C - calcium hydroxide
d d d d
D - calcium sulfate - ANSWER:*C*
d d d d d
These compounds all contain 1 mole of calcium, which has an Ar of 40.1 and therefore a molar
d d d d d d d d d d d d d d d d d d
mass of 40.1 g mol^-1d d d d
So, the aim of the game is to work out which negative ion [anion] has the lowest Mr
d d d d d d d d d d d d d d d d d d
You can immediately rule out calcium sulfate and calcium nitrate, as they both have a very high
d d d d d d d d d d d d d d d d d
Mr so a very low % of calcium in them
d d d d d d d d d
The formula of calcium carbonate is CaCO3
d d d d d d
The formula of calcium hydroxide is Ca[OH]2
d d d d d d d
You can immediately tell which ion has the lowest Mr...
d d d d d d d d d
Q5 >>> 0.0200 mol of calcium oxide is reacted completely with 2.00 mol dm-3 HCl. What is the
d d d d d d d d d d d d d d d d d d
volume, in cm3, of 2.00 mol dm-3 HCl required for this reaction?
d d d d d d d d d d d d
A - 15
d d d
B - 20
d d d
C - 30
d d d
D - 60 - ANSWER:*B*
d d d d
moles = conc x vol, and vol in cm3 = vol in dm3 x 1000
d d d d d d d d d d d d d d
1. Work out the equation first to work out the stoichiometry of the reaction:
d d d d d d d d d d d d d
2HCl + CaO >>> CaCl2 + H2O [2 : 1 molar ratio of HCl : CaO]
d d d d d d d d d d d d d d d d
d d d d d d d d d
Questions With Mark Scheme d d d
Q1 >>> Which atom is not an isotope of iodine ? [refer to the QP for the table] - ANSWER:*D*
d d d d d d d d d d d d d d d d d d d
Iodine has a proton number of 53
d d d d d d
Atom D [The element tellurium] has a proton number of 52
d d d d d d d d d d
Q2 >>> What is the bonding between the ligands and the metal ion in [Fe(H2O)6]2+ ?
d d d d d d d d d d d d d d d d
A - Metallic
d d d
B - Ionic
d d d
C - Hydrogen
d d d
D - Dative covalent - ANSWER:*D*
d d d d d
Ligand - metal ion bonds are coordinate bonds, which is a type of dative covalent bond
d d d d d d d d d d d d d d d
Q3 >>> What is the oxidation number of Mn in K2MnO4 ?
d d d d d d d d d d d d
A - +4
d d d
B - +5
d d d
C - +6
d d d
D - +7 - ANSWER:*C*
d d d d
, The 2x K+ ions each have an oxidation state of +1 so 1 x 2 = +2
d d d d d d d d d d d d d d d d d
The 4x O^2- ions each have an oxidation state of -2, so 2 x 4 = -8 in total
d d d d d d d d d d d d d d d d d d
-8 + +2 = -6, so an oxidation number of +6 is needed, as the overall oxidation state is 0
d d d d d d d d d d d d d d d d d d d
Q4 >>> Which calcium compound contains the greatest percentage by mass of calcium ?
d d d d d d d d d d d d d d
A - calcium carbonate
d d d d
B - calcium nitrate
d d d d
C - calcium hydroxide
d d d d
D - calcium sulfate - ANSWER:*C*
d d d d d
These compounds all contain 1 mole of calcium, which has an Ar of 40.1 and therefore a molar
d d d d d d d d d d d d d d d d d d
mass of 40.1 g mol^-1d d d d
So, the aim of the game is to work out which negative ion [anion] has the lowest Mr
d d d d d d d d d d d d d d d d d d
You can immediately rule out calcium sulfate and calcium nitrate, as they both have a very high
d d d d d d d d d d d d d d d d d
Mr so a very low % of calcium in them
d d d d d d d d d
The formula of calcium carbonate is CaCO3
d d d d d d
The formula of calcium hydroxide is Ca[OH]2
d d d d d d d
You can immediately tell which ion has the lowest Mr...
d d d d d d d d d
Q5 >>> 0.0200 mol of calcium oxide is reacted completely with 2.00 mol dm-3 HCl. What is the
d d d d d d d d d d d d d d d d d d
volume, in cm3, of 2.00 mol dm-3 HCl required for this reaction?
d d d d d d d d d d d d
A - 15
d d d
B - 20
d d d
C - 30
d d d
D - 60 - ANSWER:*B*
d d d d
moles = conc x vol, and vol in cm3 = vol in dm3 x 1000
d d d d d d d d d d d d d d
1. Work out the equation first to work out the stoichiometry of the reaction:
d d d d d d d d d d d d d
2HCl + CaO >>> CaCl2 + H2O [2 : 1 molar ratio of HCl : CaO]
d d d d d d d d d d d d d d d d
